Self-sustained biophotovoltaic system for hydrogen production Alicia Mier-Jimenez a,b , Jiahui Guo, Ming-Shui Yao c , Falk Harnisch b , Bin Lai a a BMBF junior research group Biophotovoltaics, Department of Microbial Biotechnology, Helmholtz Centre of Environmental Research, 04318 Leipzig, Germany, b Electrobiotechnology Group, Department of Microbial Biotechnology, Helmholtz Centre of Environmental Research, 04318 Leipzig, Germany, c Semiconductive Soft Porous Interface Group, State Key Laboratory of Mesoscience and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China In the face of the climate crisis, there is an urgent need for integrative and sustainable solutions to address the challenges of power supply. Planktonic-biophotovoltaic (BPV) systems utilize natural oxygenic photosynthetic metabolism to convert solar energy into electricity or chemical energy. Photosynthetic electrons, originated from water split driven by solar energy, can be transferred outside of the cell membrane to anode via a process called extracellular electron transfer involving redox chemical as the mediator, where those electrons are transferred to a cathode via an external electrical circuit, thus electricity being produced, or to e.g. reduce protons to hydrogen, a carbon-free liquid fuel. The ultimate objective of my PhD project is to develop a bias-free BPV system for electrocatalytic hydrogen production, which combines natural oxygenic photosystem and artificial photoelectrocatalyststo maximize the light absorption and system energy efficiency. To achieve that, we started with applying a photocathode with the aim to drive hydrogen evolution at the cathodeand simultaneously the mediator (here ferricyanide used as model chemical) recycling at the anode. The material was characterized by a Linear Sweep Voltammetry to understand the hydrogen evolution reaction under dark/light conditions. Subsequently, a chronoamperometry was conducted to assess the ferrocyanide evolution rate at the anode chamber. Finally, the optimum abiotic working system will be inoculated with cyanobacteria Synechocystis sp. PCC 6803, to balance the energy and mass flow between the abiotic and biotic components in the system and thus optimize the system performance. This preliminary data demonstrates that the implementation of a photocathode enhances the overall current production of the system and the rate of ferrocyanide oxidation at the anode under illuminated conditions. This finding also suggests a positive impact on current production when cyanobacteria cells are added. This work develops a concept of integrating bio- and photochemical materials to maximize the light energy utilization. References 1. B. Lai, H. Schneider, J. Tschörtner, A. Schmid and J. O. Krömer, Technical-scale biophotovoltaics for long-term photo-current generation from Synechocystis sp. PCC6803, Biotechnol Bioeng , 2021, 118, 2637–2648. 2. Reilly-Schott, J. Gaibler, Y. Bai, A. Mier-Jimenez, M. Qasim and B. Lai, Electron Leaks in Biophotovoltaics: A Multi- Disciplinary Perspective, ChemCatChem , DOI:10.1002/cctc.202400639. 3. Morgante, N. Vlachopoulos, L. Pan, M. Xia, C. Comninellis, K. Sivula, M. Graetzel and F. Fischer, Cuprous oxide- Shewanella mediated photolytic hydrogen evolution, Int J Hydrogen Energy , 2025, 101, 731–740. 4. M. Morgante, N. Vlachopoulos, A. Hagfeldt and F. Fischer, Microbial bioelectrochemical cells for hydrogen generation based on irradiated semiconductor photoelectrodes, IOP Publishing Ltd, 2021, preprint, DOI: 10.1088/2515-7655/ac01bd.
P62
© The Author(s), 2025
Made with FlippingBook Learn more on our blog